In a world where gigapixel images are increasingly common, what makes this 570 megapixel behemoth worthy of the crown of "most powerful"? Because it's also incredibly sensitive:

The Dark Energy Camera is the most powerful survey instrument of its kind, able to see light from over 100,000 galaxies up to 8 billion light years away in each snapshot. The camera’s array of 62 charged-coupled devices has an unprecedented sensitivity to very red light, and along with the Blanco telescope’s large light-gathering mirror (which spans 13 feet across), will allow scientists from around the world to pursue investigations ranging from studies of asteroids in our own Solar System to the understanding of the origins and the fate of the universe.

The survey is set up to try and analyze why the expansion of the universe is speeding up, and starting in December (after the camera is fully tested), a five year study will begin, surveying "one-eighth of the sky, or 5,000 square degrees, to discover and measure 300 million galaxies, 100,000 galaxy clusters and 4,000 supernovae."

As impressive as this telescope is, there's something even more impressive in the works. The The SLAC (Stanford Linear Accelerator Center) National Accelerator Laboratory is working on the Large Synoptic Survey Telescope camera, which will grab 3.2 gigapixel images, which will be released to the public. Construction of that behemoth is hoped to start in 2014.